1. The Field of the Invention
The present invention relates to catheter systems and more particularly to drainage catheter systems that are used for draining bodily fluids from a patient. The present invention is also directed to methods for coupling a drainage catheter system to a patient""s body and decoupling the drainage catheter from the body.
2. The Prior State of the Art
One of the traditional methods for draining bodily fluids includes inserting a catheter into a cavity of a patient""s body. The catheter is typically introduced either over a previously inserted guide wire or by direct puncture. Catheters are used in procedures for draining bodily fluids from, by way of example, the kidneys, the liver, and from other organs. Catheters are also used to drain bodily fluid from the chest, abdominal cavities, and from abscesses located in various areas of the body. One of the challenges of using a catheter for draining bodily fluid is its propensity to be accidentally removed from a patient""s body. Catheters have traditionally included straight tubing that, upon movement of the patient or accidental collision, can escape the patient""s body. In order to prevent displacement of the tubing from the patient""s body, various catheters have been developed that are configured to be anchored inside the patient""s body.
FIGS. 1A-1C provide an example of the traditional method for forming a loop at the distal end of the tubing in order to prevent displacement of the tubing from a patient""s body. In FIG. 1A, a traditional drainage catheter is illustrated generally as catheter 1, which includes hub 2 and tubing 3. As illustrated, one end (not shown) of a cord, such as cord 4, is affixed to the inside of hub 2, while the opposing end of cord 4 extends through tubing 3. Cord 4 extends from hub 2 inside tubing 3, then out of an exit opening at the distal end of the tubing such as opening 7. Cord 4 then extends back into a side entrance opening such as opening 6, through tubing 3 and out of the proximal end of hub 2, such that a free end of cord 4 is disposed outside hub 2, as shown in FIG. 1A.
Upon inserting catheter 1 into the patient""s body, the free end of cord 4 that protrudes out of hub 2 can be pulled tight, causing a loop to be formed in tubing 3, as illustrated in FIG. 1B as loop 9. Loop 9 maintains catheter 1 within the selected portion of the body. The bodily fluid drains into the catheter via entrance openings such as openings 5 illustrated in FIGS. 1A-1C. Once the bodily fluid drains into the entrance openings, the fluid flows down tubing 3, and out of hub 2.
Cord 4 must maintain its tension in order for loop 9 to remain in the tubing. Therefore, traditional methods have included securing the free end of cord 4 after it has been pulled tight. As such, cord 4 is able to maintain its tension during the period that bodily fluid is drained from the patient. One of the methods for securing cord 4 after it has been pulled tight includes tying the free end of cord 4 to a fixed object, such as hub 2 of catheter 1, as illustrated in FIG. 1B at knot 8. However, while tying the free end of cord 4 to a fixed object maintains the tension in cord 4, problems arise with this traditional method.
One problem experienced by practitioners using this traditional method is that the process of tying the free end of cord 4 can become cumbersome. At times the challenge of securing cord 4 is so great that the free end cannot be tied. Moreover, when cord 4 is tied and secured, the knot can have tendencies to slip, thereby causing the tension in the cord to decrease. The decrease in cord tension causes the loop to relax.
Another problem with the traditional method includes a risk that is presented after the practitioner secures the free end of the cord. Once the cord is secured, the excess is cut off with a sharp instrument. The risk presented includes that the sharp instrument used to cut off the excess cord can cause an accidental laceration to the practitioner.
Another problem with the traditional method occurs during the extraction of the catheter from the patient""s body. Under a traditional drainage catheter design, and as further illustrated in FIG. 1C, a cord, such as cord 4, extends through the tubing, exits through opening 7 located at the distal end of the tubing, and re-enters a side opening of the tubing at opening 6. Throughout the period of drainage into entrance openings, such as opening 5, cord 4 is exposed to bodily fluid, causing cord 4 to become encrusted. At the time when the tubing is to be removed from the patient""s body, the encrustation of cord 4 can prevent tubing 3 from straightening out, thereby restricting the catheter from being easily removed from the patient. Therefore, the encrusted cord causes increased difficulty when extracting the catheter from the patient""s body.
Another problem with the traditional method is presented when the catheter needs to be relocated, replaced, or removed. Once cord 4 is secured, it can be difficult to untie knot 8 of FIG. 1B. Therefore, the practitioner""s ability to relocate, replace, or remove the catheter is restricted because of the difficulty to untie knot 8. Moreover, if the excess of cord 4 has been cut off, the cord may no longer be long enough to allow the catheter to be relocated.
It would, therefore, be an advancement in the art to be able to secure the catheter without having to tie the free end of a cord. It would also be desirable if the process of securing the catheter were simplified. Furthermore, it would be desirable if the process of securing the catheter could be performed by one hand. It would be an advancement in the art if the method of affixing the cord prevented any slippage that would cause the tension in the cord to relax. It would also be desirable if once secured, the excess cord did not have to be trimmed. Moreover, it would be an advancement in the art if the removal of the catheter from the patient""s body was not affected by the encrustation of the cord.
The present invention is directed to drainage catheter systems, and to methods for coupling a drainage catheter system to a patient and decoupling the drainage catheter system from the patient. The invention overcomes the above-mentioned difficulties by facilitating the process of securing a catheter to the patient""s body, and by facilitating the removal of the catheter from the body.
Implementation of the present invention takes place in association with a catheter, such as a drainage catheter used for draining bodily fluid from a patient. Embodiments according to the present invention include an elongate hollow cannula having a proximal end and a distal insertion end, a hub that can be placed in either an extended or contracted position, and a cord that extends from the hub and within at least a portion of the cannula. The cannula includes openings so that bodily fluid can enter. Once the bodily fluid enters the cannula, the fluid drains down the inside of the cannula and out of the hub.
The cord has first and second opposing ends and an intermediate portion therebetween. The cord extends within at least a portion of the cannula and can be attached to the distal insertion end of the cannula in a variety of manners. In one embodiment, one end of the cord is attached to the hub with the intermediate portion of the cord extending through the cannula, exiting a side opening in the cannula, entering a first opening in the distal insertion end of the cannula, exiting a second opening in the distal insertion end of the cannula, and extending down through the cannula, with the second end of the cord attached to the hub. Optionally, the cord can resemble a lasso, having a loop on a first end that is fastened to the distal insertion end of the cannula. The cord then enters the cannula through a side opening and the second end is attached to the hub.
In another embodiment, a wire extends longitudinally through at least a portion of the cannula and can be used to secure the cord. In this embodiment, a first end of the cord is attached to the hub and the intermediate portion of the cord extends down the cannula, out an opening at the distal end of the cannula, through a side opening in the cannula, loops around the wire, exits the cannula through the side opening, reenters the cannula through the opening at the distal end of the cannula, and extends along the length of the cannula to the hub, with the second end of the cord attached to the hub. Similarly, the cord can resemble a lasso, with a loop at a first end. A wire extends through the loop to secure the cord. The cord extends out of a side opening of the cannula, re-enters the cannula through a distal opening, and extends down the cannula, with the second end of the cord attached to the hub.
The catheter cannula can be inserted into a patient""s body by way of a previously inserted guide wire, or by direct puncture, for example. Once inside of the patient""s body, the catheter can be coupled to the body by pressing a proximal hub member towards a distal hub member to place the hub into a compressed position. In one embodiment, by pressing the proximal hub member towards the distal hub member, one or more fingers within the proximal hub member pushes the cord into channels within the distal hub member, causing the cord to create a force upon the distal insertion end of the cannula, in the direction of the hub. The force causes the distal insertion end of the cannula to form a loop that prevents the removal of the catheter from the patient""s body. In one embodiment, the proximal and distal hub members can be locked together in the contracted position for as long as the catheter is to be coupled to the body.
To permit extraction of the catheter, the tension is eliminated from the cord. In the embodiments employing a wire, the wire is moved in a proximal direction in the cannula, thereby releasing the cord from the wire, eliminating the tension in the cord, and enabling the removal of the catheter cannula from the body. In another embodiment, a tear through material is employed in the cannula. In this embodiment, the cord can be pulled to cause the cord to tear through the distal insertion end of the cannula, thereby eliminating the tension in the cord and enabling the removal of the cannula from the patient""s body. In yet another embodiment, the proximal and distal hub members are unlocked and slid apart to eliminate the tension in the cord and to enable uncurling of the catheter distal insertion end and the removal of the cannula from the patient""s body.
Additional features and advantages of the present invention will be set forth in the description that follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.